package rpc2;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.AMQP.BasicProperties;

public class RPCServer {
	private static final String RPC_QUEUE_NAME = "rpc_queue_1";
	  
	  private static int fib(int n) {
	    if (n ==0) return 0;
	    if (n == 1) return 1;
	    return fib(n-1) + fib(n-2);
	  }
	    
	  public static void main(String[] argv) {
	    Connection connection = null;
	    Channel channel = null;
	    try {
	      ConnectionFactory factory = new ConnectionFactory();
	      factory.setHost("10.20.53.22");
	  
	      connection = factory.newConnection();
	      channel = connection.createChannel();
	      
	      channel.queueDeclare(RPC_QUEUE_NAME, false, false, false, null);
	  
	      channel.basicQos(1);
	  
	      QueueingConsumer consumer = new QueueingConsumer(channel);
	      channel.basicConsume(RPC_QUEUE_NAME, false, consumer);
	  
	      System.out.println(" [x] Awaiting RPC requests");
	  
	      while (true) {
	        String response = null;
	        
	        QueueingConsumer.Delivery delivery = consumer.nextDelivery();
	        
	        BasicProperties props = delivery.getProperties();
	        BasicProperties replyProps = new BasicProperties
	                                         .Builder()
	                                         .correlationId(props.getCorrelationId())
	                                         .build();
	        
	        try {
	          String message = new String(delivery.getBody(),"UTF-8");
	          int n = Integer.parseInt(message);
	  
	          System.out.println(" [.] fib(" + message + ")");
	          response = "" + fib(n);
	        }
	        catch (Exception e){
	          System.out.println(" [.] " + e.toString());
	          response = "";
	        }
	        finally {  
	          channel.basicPublish( "", props.getReplyTo(), replyProps, response.getBytes("UTF-8"));
	  
	          channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
	        }
	      }
	    }
	    catch  (Exception e) {
	      e.printStackTrace();
	    }
	    finally {
	      if (connection != null) {
	        try {
	          connection.close();
	        }
	        catch (Exception ignore) {}
	      }
	    }      		      
	  }
}
